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Test D: Automatic Dimming Function Inoperative

  1. Place transmission in Park. Turn ignition switch to RUN position. Cover light sensor on rear of inside mirror. If inside mirror does not darken, go to next step. If inside mirror darkens and driver mirror does not darken, go to step 7). If both mirrors darken, system is operating properly at this time.
  2. Turn ignition switch to LOCK position. Disconnect inside mirror harness connector. Turn ignition switch to RUN position. Measure voltage at terminal No. 7 (Dark Blue/Light Green wire) at inside mirror harness connector. See Fig 1 . If battery voltage exists, go to step 5). If battery voltage does not exist, go to next step.
  3. Turn ignition switch to LOCK position. Remove fuse No. 8 (7.5-amp) from instrument panel fuse box. If fuse is okay, repair open in Dark Blue/Light Green wire. If fuse is blown, go to next step.
  4. Measure resistance between ground and terminal No. 7 (Dark Blue/Light Green wire) at inside mirror harness connector. If resistance is 10,000 ohms or less, repair short to ground in Dark Blue/Light Green wire and retest. If resistance is more than 10,000 ohms, replace inside mirror and retest.
  5. Measure resistance between ground and terminal No. 6 (Black wire) at inside mirror harness connector. If resistance is more than 5 ohms, repair open in Black wire and retest. If resistance is 5 ohms or less, go to next step.
  6. Turn ignition switch to RUN position. Ensure transmission is in Reverse. Measure voltage at terminal No. 5 (Black/Pink wire) at inside mirror harness connector. If battery voltage exists, replace inside mirror and retest. If battery voltage does not exist, repair open in Black/Pink wire and retest.
  7. Disconnect inside mirror harness connector. Turn ignition switch to LOCK position. Test driver mirror dimming by connecting positive terminal of a "D" size battery (1.5 volts or less) to terminal No. 4 (Purple wire) and negative terminal of battery to terminal No. 3 (Light Blue/White wire) at inside mirror harness connector. See Fig 1 . If driver mirror darkens, go to next step. If driver mirror does not darken, replace driver mirror glass and retest.
  8. Turn ignition switch to LOCK position. Disconnect driver mirror harness connector. Connect inside mirror harness connector. Measure voltage at terminal No. 9 (Light Blue/White wire) at driver mirror harness connector. See Fig 1 . If battery voltage exists, go to next step. If battery voltage does not exist, go to step 10).
  9. Disconnect inside mirror harness connector. Measure voltage at terminal No. 9 (Light Blue/White wire) at driver mirror harness connector. If battery voltage exists, repair short to voltage in Light Blue/White wire. If battery voltage does not exist, replace inside mirror and retest.
  10. Measure voltage at terminal No. 10 (Purple wire) at driver mirror harness connector. If battery voltage exists, go to next step. If battery voltage does not exist, go to step 12).
  11. Disconnect inside mirror harness connector. Measure voltage at terminal No. 10 (Purple wire) at driver mirror harness connector. If battery voltage exists, repair short to voltage in Purple wire and retest. If battery voltage does not exist, replace inside mirror and retest.
  12. Measure resistance between ground and terminal No. 9 (Light Blue/White wire) at driver mirror harness connector. If resistance is 10,000 ohms or less, go to next step. If resistance is more than 10,000 ohms, go to step 14).
  13. Disconnect inside mirror harness connector. Measure resistance between ground and terminal No. 9 (Light Blue/White wire) at driver mirror harness connector. If resistance is 10,000 ohms or less, repair short to ground in Light Blue/White wire. If resistance is more than 10,000 ohms, replace inside mirror and retest.
  14. Measure resistance between ground and terminal No. 10 (Purple wire) at driver mirror harness connector. If resistance is 10,000 ohms or less, go to next step. If resistance is more than 10,000 ohms, go to step 16).
  15. Disconnect inside mirror harness connector. Measure resistance between ground and terminal No. 10 (Purple wire) at driver mirror harness connector. If resistance is 10,000 ohms or less, repair short to ground in Purple wire and retest. If resistance is more than 10,000 ohms, replace inside mirror and retest.
  16. Disconnect inside mirror harness connector. Measure resistance in Light Blue/White wire between terminal No. 3 at inside mirror harness connector and terminal No. 9 at driver mirror harness connector. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in Light Blue/White wire and retest.
  17. Measure resistance in Purple wire between terminal No. 4 at inside mirror harness connector and terminal No. 10 at driver mirror harness connector. If resistance is 5 ohms or less, replace inside mirror. If resistance is more than 5 ohms, repair open in Purple wire and retest.
Fig 1: Identifying Inside Mirror Harness Connector Terminals
G98D01586Courtesy of FORD MOTOR CO.
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